Lord Henley succeeded to the peerage in 1977 upon the death of his father. An Irish peer, he is able to sit in the House of Lords by virtue of a United Kingdom peerage granted to the 3rd Baron Henley, namely Baron Northington.

With the passage of the House of Lords Act 1999, Lord Henley along with almost all other hereditary peers lost his automatic right to sit in the House of Lords. He was however elected as one of the 92 hereditary peers to remain in the House of Lords pending completion of House of Lords reform.